Multiglazed window and light screen therefor



Patented Apr. 22, 1941 MULTIGLAZED WINDOWAND LIGHT SCREEN THEREFOR Percy E. Knudsen, Pittsburgh, Pa., assignor to Pittsburgh Plate Glass Company, Allegheny County, Pa., a corporation of Pennsylvania Application January 26, 1939, Serial No. 252,915

3 Claims. (ciao-56.5)

vThe present invention relates to windows and notably to windows of the multiglazed type.

One object of the invention is to provide a frame construction for a multiglazed window which is simple in design, which is of low conductivity to heat and in which one or more of the plates or panes of glass can be removed to admit of access to the interior of the construction without disturbing the companion pane or panes.

A second'object of the invention is to provide a multiglazed window construction by means of which light can be intercepted exteriorly of the building employing it, or optionally admitted in any desired intensity.

A third object'of the invention is to provide a construction of the foregoing type invwhi ch the light-excluding and regulating means is protected from dust and air.

These and other objects of the invention will be apparent from consideration of the following specification and the appended claims.

It has heretofore been recognized that conventional windows involving a single plate or pane of glass were relatively ineflicient barriers to the transmission of heat to or from the interior of buildings in which they were installed. For example, the outer surface of the glass, during cold weather, became chilled and in turn caused chilling of the atmosphere within the buildings in which the windows were employed. Conversely when the/atmosphere without the buildings was warmer than the air within the because it admits of cleaning of the glass without completely opening the buildings in which the glass is employed to the atmosphere.

Although multiglazed windows involving two or more spaced plates of glass substantially reduce conduction and convectional transmission of heat to or from the interior of a building; such constructions within themselves do not constitute satisfactory barriers to radiant heat to which the glass is transparent. One conventional method of excluding this type of heat has involved the provision of screens or shades secured within the building in which the windows are employed. By use of such screens the amount of light transmitted through the units can be regulated fairly satisfactory. However, the screens act as collectors of dust and, moreover, in warm weather the screens become heated by radiant heat absorbed and, in turn, heat the indoor air. Of course after the heat once gains -'access to the interior of a building, it cannot buildings heat was transmitted from the exterior to the interior.

In order to obviate this type of heat transfer it has been proposed to provide windows having a plurality of sheets or panes of glass so spaced with'respect to each other as to provide insulated dead air chambers. By use of this type of construction heat transfer by conduction and convection was substantially reduced. However, it was found difficult to exclude moisture from the interiors of such multiglazed windows and in time moisture produced a permanent haze upon the glass. .Moreover, the frames usually included metallic parts which were improperly insulated and provided paths for transmission of heat to and from the interiors of the buildings. Chilled metallic surfaces within the buildings were thus provided and these constituted zones for objectionable condensation of moisture.

The present invention includes as one feature the provision of a simple frame and clamping structures for multiglazed units, in which all highly conductive parts are effectively insulated and which by proper manipulation will permit certain of the sheets tobe removed from the frames to give access to the interiors without disturbing the other plates. This is desirable be removed except by refrigerating apparatus or other cooling devices. For this reason it is preferable to intercept it before it gains access to the interior.

In accordance with one of the features of the present invention, the foregoing difliculties are substantially obviated by provision of louver-like screens so mounted between the sheets or panes of glass of multiglazed units as to admit of control of the amount of light passing through the windows and, also, to intercept radiant heat before it gains access to the interior of the building inwhich the units were employed.

Fora better understanding of the invention reference may now be had to the accompanying drawing in which the single figure is a fragmentary cross-sectional view through a portion of the window embodying theinvention. In the drawing like numerals refer to like partsthroughout.

In the drawing a wall construction In of conventional design defines a window opening, the edges of which are capped or crowned by a layer ll of cement or other suitable facing material. Only the bottom portion or sill structure of the frame of the window is disclosed. However, it will be apparent that the jambs or sides and the top or lintel structure are essentially the same and need not be described. The structure includes a bar I2 disposed upon the facing material and comprising a strip of metal such as steel or aluminum. This strip as shown comprises a horizontal web-like rear section I 3 and a downwardly-extending flange I 4 comprising a portion 'replicately upwardly bent to provide upper vertical flange l6. The upper marginal portion of the latter is horizontally offset to provide a shoulder l1 and a lip I8. Holes 19 may be provided in shoulder I 1 to permit escape of any moisture that may condense in or run into the space back of the lip. Pane or plate 22 of glass maintained from inward displacement from the shoulder by means of clip-like member 23, which is inwardly sprung away from the glass to receive a plastic packing.24 that acts as a seal to prevent .the entrance of air and moisture to the interior of the, construction. The lower portion of the clip 23 is secured between the inner face of flange l6 and the outer edge of wooden sill or bar 26 that rests upon and constitutes an insulative covering for section l3 of bar l2. If desired the edge may be covered by means of a metallic plate 21 of inverted L cross-section.

Bar 28 is secured from inward displacemen from bar l2 "by means of a shoulder or lip 28, upwardly bent along the rear margin of the web l3 and engaging a corresponding slot formed in the,

lower face of the bar. A spaced sheet or a plurality of spaced sheets of glass 29 are mounted vide one or more closed insulative chambers. In

the construction illustrated two sheets or plates are secured in spaced relation to provide a conventional double-glazed unit by means of a marginal frame 3|, comprising spaced channels 32 and 33. interconnected by a web 34. The space about the edges of the glass within the channels may bepacked or sealed-by means of tape "or sealing composition of any convenient type.

The two spaced plates of glass are secured as a unit upon the edge of the sill by means of a construction involving a plate 36 having a downwardly-extending exterior flange 31 and an upwardly-extending interior flange 38, which provides an abutment for the frame of the; glass. Flange 39 is also provided with a lip 39, the marginal portion 4| of which is downwardly directed into a slot formed in the upper face of the bar 26.

Cover plates or strips 42 are secured to the bar 26 by means of bolts 43 extending through suitable transverse openings in the bar and threaded at their inner extremities through openings in the downwardly-extending lip' 4|. By suitably tightening the bolts the cover plate is drawn inwardly to press the frame 3| against the abutment 38.

A suitable screen structure for use within the chamber between the plate 22 and the inner of the plates 29, to regulate the admission of light, comprises louver-like slats orbars 45, which rotate or tilt about axially disposed pivots 46 journaled in the jambs of the units.

Mechanism for tilting the bars includes a vertical bar 41 which is pivoted .as indicated at 48 to the ends of the bars 45, at points slightly offset with respect to the pivots 46. At its lower extremity bar 41 is pivoted upon a crank-pin 49 upon the face of a worm-gear 50 that rotates within slot 5| in bar 26, upon a horizontal shaft 62. The shaft has bearings in the end of bar 26 and in a cover plate 53 for slot 5| which is secured to the bar by means of screws 54 or other suitable fastening devices. The worm-gear is rotated about its axis by means of a worm 56, secured upon the inner extremity of a shaft 51 which rotates in a transversely and upwardly-extending opening in the bar 26. At its outer extremity the shaft extends through a suitable stufiing box 59 which is designed to seal the passage about the shaft from the entrance of air or moisture. The projecting portion of the shaft may be provided with'a knurled head 59, by means of which the shaft may be rotated in turn to rotate the worm-gear 5|. As thelatter is rotated the shaft 41 is oscillated to cause tilting of the bars 45 about their horizontal axes. It will beobserved that the bars may be tilted so that either face thereof is directed to the exterior of the construction. If desired one face may be covered with a highly reflective material such as aluminum paint, which is susceptible of reflecting back most of the light and heat striking it. The face of the members may be coated with a black or dark composition designed to absorb a large proportion of the radiant energy striking it.

It will be observed that in the construction described insulative bar 26 completely covers all metallie parts that are exposed to the exterior of the building; this obviates condensation of moisture upon metallic parts. Bars 45 may, when desired, be so adjusted as to absorb or reflect back radiant heat and light before it enters the building. Therefore, it does not increase the temperature of the building. The bars by reason of their positions within the units are protected from dust and decay. The bars when tilted also tend to divide the compartment in which they are disposed into a series of small cells which are more effective as barriers to passage of heat than a single large space.

Panes 29 are readily removable as a unit to admit of repair or changes in the louver construction and, also,.to admit of cleaning the inner surfaces of the glass.

Although only the preferred form of the invention has been shown and described, it will be apparent that this is only illustrative, and

numerous modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

What I claim is:

l. A triple-glazed window construction comprising a frame and three spaced parallel sheets of glass disposed therein and providing inner and outer sealed-dead air chambers, a screen structure disposed in the outer dead air chamber and being adjustable to regulate the amount of heat and light passing through the construction and means operable externally of the construction for adjusting the screen.

2. A window construction as defined in claim 1 in which the screen is of Venetian blind type and comprises spaced parallel bars pivoted in the frame to rotate about their longitudinal axis, the

means to adjust the screen comprising a rod interconnecting the bars for simultaneous rotational movement and a control element connected to the rod and projecting externally of the construction for manual activation to move the rod.

3. A triple-glazed window constructionas defined in claim 1 in which the two inner of the sheets of glass are secured together by channel means independent of the outer of the sheets of glass and provide an independently sealed double glazed unit and means to secure said unitinto the frame in spaced relation to the outer of the sheets, the unit being removable in assembled relation independently of said outer sheet to give access to the screen structure disposed between the outer chamber. v

PERCY E. KNUDSEN. 

